In conventional wireless LANs, user devices such as personal computers and personal digital assistants (PDAs) communicate with access point (AP) devices in accordance with specified standards. One such standard is described in the Institute of Electrical and Electronics Engineers (IEEE) 802.11b standards document, which is incorporated by reference herein. The 802.11b standard supports data rates of up to 11 Mbps in the 2.4 GHz industrial, scientific and medical (ISM) band, using direct sequence spread spectrum (DSSS).
Efforts have been made to increase the data bandwidth capabilities of wireless LAN standards such as 802.11b. For example, the 802.11a standard has recently been developed, which supports data rates of up to 54 Mbps in the 5 GHz band using orthogonal frequency division multiplexing (OFDM). Another recently-developed standard is 802.11g, which can support data rates of up to 54 Mbps in the 2.4 GHz band, using DSSS for data rates below 20 Mbps, and OFDM for data rates above 20 Mbps. The 802.11a and 802.11g standards documents are also incorporated by reference herein.
A significant problem that arises in conventional wireless LANs such as those described above is that it is often difficult for a mobile user to determine an appropriate location within the network for achieving maximum data throughput. It is well known that data throughput is influenced by a number of factors, such as received signal strength and received signal quality, which can vary greatly from location to location within the coverage area of a given access point device or set of access point devices. Typically, a user device in a wireless LAN is configured so as to include meters for signal strength and signal quality, which provide a visual indication of these factors in terms of percentages of specified maximum values.
In many situations, a user has a number of different choices in terms of selecting a possible location for interaction with an access point. For example, this is generally the case in public “hot spots,” such as those provided in a coffee shop, airport or train station, where the user could sit in any of a number of different locations. In these and other similar situations, the user can simply walk about the area while monitoring the meters on the device display, and thereby eventually determine an appropriate location suitable for maximizing data throughput. Unfortunately, the user in this approach is essentially on his or her own, individually determining an appropriate location by trial and error using the meters mentioned above, without any proactive assistance whatsoever from the network. Any mistakes made by one user in his or her determination may be repeated by many other users.
Moreover, public environments of the type described above may be subject to frequent environmental changes, such as the adding or dropping of users, and time-varying levels of electronic interference or signal reflections. As a result, it may be necessary for a given user to periodically repeat the trial-and-error optimization procedure.
Accordingly, a need exists for alternative techniques for determining appropriate locations for user devices in a wireless network, so as to achieve enhanced data throughput without the above-noted difficulties associated with the conventional trial-and-error approach to individualized location determination.